The Principle Investigator initiated this program on his appointment to the Radiation Oncology Department of Oregon Health Sciences University with the first "OHSU Experimental Radiation Oncology Conference" held on March 16th and 17th 1989. His prior experience as the organizer of two similar meetings at the University of Wisconsin, Madison in 1975 and 1981 contributed greatly to the success of the first Portland Conference. The response by both the scientific and medical communities to this first Oregon meeting (program enclosed demonstrated a need in Portland and the Northwest for a forum which would provide an integrated approach to cancer- related topics. The stimulus of the meeting and the recent initiation of a radiobiology program on the OHSU campus has increased local interest and awareness of experimental cancer studies. Continuing these "Experimental Radiation Oncology Conferences" would further increase this interest and awareness. Attendance at the 1989 Portland meeting was not only local. It involved the medial and research communities state-wide and participants both from out of state and from Europe and this provided an opportunity for researchers from Portland (and the West Coast States generally) to exchange ideas with invited speakers chosen for their innovative work. A number of internationally recognized workers were able to attend the Portland Conference as it had been scheduled as a satellite of the 1989 Radiation Research meeting. Such a link will be retained to maximize the benefits while keeping travel costs for invited speakers to an acceptable level. Funds for the first conference were primarily provided by the "Clifford V. Allen" fund set up to honor the first Chairman of the OHSU Radiation Oncology Department on his retirement. This fund, and other limited local resources, are now insufficient to support a further meeting. The present grant request recognizes the need to continue these conferences and to build on the success of the first meeting. The primary aim will be to stimulate awareness among Oregon physicians and medial scientists of developments in research fields which have potential therapeutic implications. Each Conference will provide an integrated approach to the topic chosen and it is anticipated that this will prove of particular interest to local clinicians. The format of the meeting and the relatively small number of participants (60-80) will maximize opportunities for interactive discussion between the various participants. The topic for the next meeting is "Intrinsic cellular sensitivity and acquired resistance to radiation, heat and drugs". this is of clinical importance and also the focus of substantial current research interest at both the basic and the applied level. The topics for meetings in subsequent years are "Biological bases of novel therapeutic approaches" and "The role of molecular biology in cancer treatments".